Sea Stars

Sea stars (also known as starfish) are in the class Asteroidea in the phylum Echinodermata, and there are over 2,000 different species worldwide. Like most echinoderms, sea stars generally have a 5-part symmetry. Most sea stars have 5 arms (or a multiple of 5) arranged around a central disk, and the mouth is located in the center of this disk on the underside (called the oral surface).
Sea stars move using the many rows of tube feet on the oral surface of each arm.

Most sea stars are generalist predators and eat anything they can catch and digest including mussels, clams, snails, barnacles, sea urchins, and even other sea stars. Usually, they evert their stomach out through their mouth and slip their stomach into their prey until the prey is digested. Then the sea star pulls its stomach back in and goes on to the next victim



When sea stars have access to a lot of food, they can grow very fast and increase in size by many magnitudes

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Interesting and Useful Sites on Sea Stars

Last modified September 23, 2005